Classical Genetics

Question 0

G2 of interphase

Answer 0

Chromosomes have been already duplicated

Centrosomes duplicate to travel to opposite ends of cell in later stages

Question 1

Stages of cell cycle

Answer 1

Interphase (g1, DNA synthesis, g2)

Mitotic phase

• mitosis (division of nucleus)
• cytokinesis (division of cytoplasm)

Question 2

Prophase

Answer 2

In nucleus, chromatin becomes chromosomes which consists of two sister chromatids

Question 3

Prometaphase

Answer 3

Spindle microtubules attach to chromosomes at kinetochore location

Question 4

Metaphase

Answer 4

Chromosomes aligned along metaphase plate

Question 5

Anaphase

Answer 5

Sister chromatids leave each other. They do this by chopping up the microtubules as it moves along to crate tubulin subunits

Non-kinetochore microtubules lengthen

Question 6

Telophase

Answer 6

Microtubules disappear

Daughter nuclei form

Forms a cleavage furrow or cell plate

Question 7

Diploid/haploid cells

Answer 7

Diploid: contains two sets of chromosomes, one from each parent

Haploid: just one

Question 8

Law of segregation

Answer 8

Two alleles of each gene separate into different gamete cells, randomly uniting to form different genotypes in the offspring.

This is what explains the 3:1 ratio when one gene is involved

Question 9

Law of independent assortment

Answer 9

Mendel noted that after segregation, alleles recombine independently of one another at fertilization

Question 10

Chromosomal theory of inheritance

Answer 10

Mandel’s laws of heredity were basically given a physical basis, as the alleles he mentioned were found to be located at loci on the chromosomes

Question 11

Incomplete dominance

Answer 11

Both alleles, when matched together, create a phenotype that appears blended (pink flowers)

Question 12

Complete dominance

Answer 12

One allele is completely dominant to the other

Question 13

Codominance

Answer 13

Both alleles are dominant and expressed, but in a different way than incomplete dominance. Instead of pink petals, you’d have white and red splotches

Question 14

Pleiotropy

Answer 14

One gene, multiple effects

Good example is sickle cell anemia

Question 15

Epistasis

Answer 15

Alleles of one gene determine the presence of other genes in an organisms phenotype, like hair pigment and coat color in mice

Question 16

Heterochromatin/euchromatin

Answer 16

H: The region of a chromosome that is darkly stained and does not contain any genes

E: contains genes, less tightly packed

Question 17

Linked genes

Answer 17

Genes that lie on the same chromosome and therefore cannot independently assort

Question 18

Sex-linked traits

Answer 18

Males are more likely to have some diseases because they only possess one X chromosome. Females are less likely because they possess two, so the second can “cover” for them

Question 19

Trisomy

Answer 19

A genetic defect that occurs when there is n+1 chromosomes in a fertilized eggs

When it happen with chromosome 21, Down’s syndrome occurs

Question 20

Aneuploidy

Answer 20

A cell with more or less than the correct diploid number of chromosomes

Question 21

Polyploidy

Answer 21

Condition where an organism has more than 2 complete sets of chromosomes

Question 22

Reciprocal translocation

Answer 22

An alteration in chromosome structure that occurs when a segment of one chromosome moves to another non-homologous chromosome

Question 23

Genomic imprinting

Answer 23

Same gene, different effect, depending on which parent it came from